The Scientific Core exists to facilitate the scientific projects within the program. The services, materials and reagents provided by the Scientific Core are purified proteins from natural and recombinant sources and scrapie prions, synthetic peptides and oligonucleotides, PrP antibodies, transgenic mouse screening and a chemical and biochemical analytical service. This core will be directed by Dr. Michael Baldwin, an analytical chemist of considerable experience who directed a core service laboratory in the University of London for 14 years and who has devoted himself for the last eight years to research into the chemistry and biochemistry of the prion protein. The preparation of purified prions has been carried out in this laboratory for more than a decade; in recent years this program has been supervised by Ms. Hana Serban. Recombinant PrP variants will be expressed in culture and purified for use in all projects. Ms. Serban will also supervise the production of PrP antibodies, crucial to the success of Projects 1, 3 and 4 and Core C. Dr. Haydn Ball, a peptide chemist of considerable experience, will synthesize peptides to be used by all the projects and for antibody production, and the synthesis of oligonucleotides for projects 1 and 4 and for screening transgenic mice. The screening of these mice, which is essential for project 1, will be carried by Ms. Ruth Koehlar. Dr. Baldwin will carry out chemical and biochemical analysis, which will benefit all the project. All of these activities are currently being carried out very successfully in this laboratory by highly experienced personnel already in post.